Petco and Petsmart have tried to reserve themselves diplomatic immunity from lawsuits from organizations like PITA by not offering items that can be determined as live foods. Good thing there are LFS with Feeders down the street hee hee.
it seems people have a hard time grasping goldfish are actually creatures of nature and not live food for other fish. 15 gallons is actually too small. ive seen "goldfish" well over 13 inches in length (not koi), and a friend of mine owned his goldfish for 12 years before it died, in which time the fish was just under a foot long.
gold fish, if kept for what they are, and not as food, will require space. you can eaisly stock goldfish in a small feeder tank with the mind set that they will be cycled out for food eventually. but for life, goldfish will require what all fish require. proper care.